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Chapter 2 . Matter. 2.1 Nature of Matter. Objectives To learn about the composition of matter To learn the difference between elements and compounds To define the three states of matter. A. The Particulate Nature of Matter. Matter is the stuff of which the universe is made of.
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Chapter 2 Matter
2.1 Nature of Matter Objectives • To learn about the composition of matter • To learn the difference between elements and compounds • To define the three states of matter
A. The Particulate Nature of Matter • Matter is the stuff of which the universe is made of. • Matter comes in many forms Ex. Stars, the air we breath, food we eat, and the Earth we live on. • Has two characteristics • Has mass • Takes up space
The Atomic Nature of Matter • All matter consists of similar tiny particles called atoms. • Atom is the fundamental unit of which elements are made of. • Ex Copper Atoms
B. Elements and Compounds • Scientist have learned that all matter is made up of 100 different types of atoms. • Nitrogen atoms are different form oxygen atoms, which in turn is different from copper atoms. • We call these 100 types of atoms the elements of the universe.
Compounds • In much the same way that we use a few letters to make thousands of words, we use atoms to construct all matter. • Just like letters combine to make different words, atoms combine to form different compounds. • Compounds are substances made by bonding atoms together in specific ways.
Compounds • Compounds are substances that contain two or more different types of atoms.
Compounds • If you could magically travel inside a glass of water and examine its parts, you would see particles consisting of two hydrogen atoms bonded to an oxygen atom. • We call this particle a molecule. • Molecule is made up of atoms that are stuck together. • All molecules of a compound are the same.
Elements • Elements contain only one type of atom – elemental copper contains only copper atoms and elemental gold contains only gold atoms.
C. The States of Matter • Matter exists in three states: • Solid: a rigid substance with a definite shape • Liquid: has a definite volume but takes the shape of its container • Gas: takes the shape and volume of its container
2.3 Classifying Matter Objectives • To learn to distinguish between mixtures and pure substances • To learn two methods of separating mixtures
A. Mixtures and Pure Substances • Virtually all the matter around us consists of mixtures of substances. • The air we breath is a mixture. • The soil is a mixture. • Even the water from a drinking fountain is mixture. How? • Matter can be classified as a mixture or a pure substance.
Mixtures • Mixture can be defined as something that has variable composition. • Examples- wood, soda, the air we breath, underground water and coffee. • The composition of mixtures varies, but the composition of compounds is always the same.
Mixtures • There are two types of mixtures. • Mixtures can be classified as heterogeneous or homogeneous mixtures. • Heterogeneous mixtures are unevenly mixed, meaning that it contains regions that have different properties from those of other regions. Ex. Sand, salad, trail mix.
Mixtures • Homogeneous mixtures are evenly mixed throughout, meaning they are the same throughout. • Homogeneous mixtures can also be called: • Solution- mixture involving a liquid • Alloy- mixture of metals
Mixtures • Alloy
Water is a compound. All the components are the same—H2O molecules. Pure Substances • A pure substance always has the same composition. • Pure substances are of two types: • Compounds which can be chemically broken down into elements • Elements which cannot be broken down chemically into simpler substances
B. Separation of Mixtures Mixtures can be separated into pure substances by various means. Distillation: involves boiling
B. Separation of Mixtures Filtration
2.2 Properties of Matter Objectives • To learn to distinguish between physical and chemical properties • To learn to distinguish between physical and chemical changes
A. Physical and Chemical Properties and Changes • Matter has both physical and chemical properties. • Chemical properties describe a substance’s ability to change to a different substance. • Physical properties are the characteristics of a substance that do not involve changing to another substance. • Examples are: shape, size and color
A. Physical and Chemical Properties and Changes • Matter undergoes physical and chemical changes. • A physical change involves a change in one or more physical properties but no change in composition.
A. Physical and Chemical Properties and Changes • A chemical change transforms a substance into one or more new substances.